Performance Assessment of Part-Electric General Aviation Aircraft
Verfasser:
Kolja Seeckt
Abgabedatum:
27.02.2006
Erster Prüfer:
Prof. Dr. Scholz
Zweiter Prüfer:
Prof. Dr. Zingel
Externer Betreuer:
Dr. Young University of Limerick
Diplomarbeit
Abstract
A study was undertaken that investigates analytically a change of a General Aviation
aircraft’s powerplant from an internal combustion (IC) engine to a hybrid engine consisting of
an IC engine plus an electric motor. For this purpose, the motor glider Aeromot AMT 200
Super Ximango was chosen as reference aircraft, and its drag polar and primary performance
characteristics (e.g. drag and drag power versus speed, range, endurance) were determined.
Afterwards, equations were determined to estimate the masses of the new IC engine and
electric motor depending on their type of construction and power output. Furthermore, a tool
in form of a Microsoft Excel spreadsheet was created to determine and compare aircraft mass,
power demand, energy consumption, energy costs and carbon dioxide (CO2) -emissions of the
reference and the hybrid aircraft. This tool can be adapted to different reference aircraft,
reference missions, battery types, fuel and electricity costs and power splits between IC
engine and electric motor. A first attempt to describe the AMT 200 by means of an idealised
parabolic drag polar showed that this leads to very poor results during cruise flight for this
type of aircraft. In a second step, another drag polar equation was used, which led to realistic
results compared to real aircraft data taken from the AMT 200’s flight manual. Large fractions
of electrically produced shaft power lead to large mass penalties of the hybrid aircraft –
especially due to a large battery mass. Nevertheless, this thesis’ reference cruise flight mission
of 2.5 h flight in 2,500 ft at a speed of 50 m/s (180 km/h, 97 kn), shows a reduction in energy
costs and CO2-emissions of an order of magnitude of 50 percent at a 50:50 power split
between IC engine and electric motor.
